Night Vision is based upon infrared technology and it uses infrared rays to locate any object present in a far distance from us during night or dark environment. Infrared rays are invisible to human eyes but there are some googles which if we wear can be able to see in dark. So wearing night vision googles a driver can become aware of an object ahead well before the driver could see it using car headlights.
What i did was multiplied 7 times 6 and that equaled 42. They all used 2 dollar off coupons. You asked what was the price of one movie ticket without the coupon, so i added $2 to 7 and got $9